Gage attachment for drills



Oct. 14, 1958 H. G. GIBBLE GAGE ATTACHMENT FOR DRILLS Filed NOV. 8, 1955 FIG.

FIG. 2

INVENTOR HOWARD G. GIBBLE ATTORNEY United States Patent 2,855,619 GAGE ATTACHMENT FOR DRILLS Howard G. Gibble, Mount Joy, Pa. Application November 8, 1955, Serial No. 545,659 Claims. (Cl. 33-46) This invention relates to a visible gage for indicating the position of an electric drill when boring a hole.

In the use of an electric drill for boring holes in wood or metal, it is diflicult in the hand operated type to be sure that the drill is normal to the surface in which the hole is being drilled. It is, of course, possible to hold an angle against the surface and hold the drill parallel to that angle. As this should be done in two planes intersecting at right angles, it is a very ditficult job to be sure that the drill is in the correct position by this mechanical means.

The object of the present invention is to provide a simple visible means of assuring the user that the drill is held normal to the surface in which the hole is being made.

It is a further object of the present invention to provide I a visible circle of lighted dots around the hole to be made which, if the drill is held normal, represents a circle and which upon the slightest inclination of the drill from the normal will indicate an oval.

It is a further object to provide a built in chamber housing a parallel light bulb which will emit rays of light through a series of holes arranged in a circle around the drill so that a series of parallel spots is directed onto the surface to be drilled, said circle to be maintained concentric with the hole being drilled assure vertical drilling.

The invention is illustrated in the accompanying drawing in which:

Figure 1 is a side elevation partly in section of a drill showing the gap device as an attachment to be clamped over the end of the drill.

Figure 2 is an end view of the device shown in Figure 1.

Figure 3 is a detail showing the invention as built into the drill.

Figure 4 is a representation of the pattern of light spots as shown on the surface to be drilled when the drill is normal to that surface.

Figure 5 is a pattern of light spots as shown when the drill is held in a position which is in normal to the surface to be drilled.

Referring particularly to Figures 1 and 2, a hand drill 8 with the usual grip 9, trigger 10 and chuck 11 is shown with the chuck centered on the motor casing. It is, of course, possible to make the attachment for those drills where the chuck is not centered on a motor casing.

A casing 12 formed of sheet metal and having a slot 13 is adapted to fit over the end of the drill 8 and to be held in position by a screw 14 and wing nut 15 engaging the extended ears 16.

The forward end of the casing is bent to form the housing 17 for a circular light bulb 18 connected to a source of electricity by the cord 19 and operating on the same current which operates the motor. The forward wall of the housing 17 is formed with a series of circular holes 19 concentric with the chuck 11. Directly in front of the light bulb 18, a partition wall 20 having holes 21 similarly arranged to the holes 19 serves to direct the rays of light to produce a distinct pattern without distortion on the workpiece.

Referring particularly to Figure 3, the motor casing 22 of a drill similar to that shown in Figure l is provided with screw threads 23 to receive a casing 24. The front wall of this casing is provided with holes 25 similar to the holes 19 of Figure l and the casing is provided with a light bulb 26 similar to the light bulb 18. A similar partition 30 directs the light rays through the holes 31. The

difference between the form shown in Figure 3 and Figure 1 is that Figure 3 is built into the casing of the drill while Figure l is an attachment which may be secured to the outside of the drill.

In using the drill the bulb 18 will light upon the plugging in of the drill and the drill positioned as shown at 28 in Figure 4. A series of illuminated spots 29 will be shown concentric with the drill on the surface which is being drilled when the drill is held in a position normal to said surface. Should the drill be held as shown at 30 in Figure 5, the spots of light 31 will form an oval ring around the hole being drilled which is at once apparent to the eye and by tilting the drill in the right direction the circle of light dots can be made concentric.

It will thus be seen that this forms a quick visible gage by which the user of an electric drill can assure himself that the hole being drilled is at right angles to the surface in which it is being drilled.

What is claimed is:

1. An attachment for a hand held electric drill comprising a casing formed with a plurality of spaced pairs of holes arranged in a circle concentric with the drill, a light source in said casing to direct the rays of light through said holes to provide a circular gauge pattern of light spots on the surface being drilled.

2. An attachment for a hand held electric drill comprising a casing formed with spaced partitions, each with a plurality of holes arranged in circles concentric with the drill, a circular light source in said casing to direct the rays of light through said holes to provide a circular gauge pattern of light spots on the surface being drilled.

3. An attachment for a hand held electric drill comprising a casing formed with a plurality of holes arranged in a circle concentric with the drill, a light source in said casing, means between said light source and said holes to screen all except rays of light substantially parallel to said drill, whereby a sharp clear image of lighted spots in the form of a circle when the drill is perpendicular to the surface being drilled is projected on the surface of the work being drilled.

4. An attachment for a hand held electric drill comprising a casing formed with a plurality of holes arranged in a circle concentric with the drill, a light source in said casing, a shield interposed between said light source and said holes to screen all except rays of light substantially parallel to said drill, whereby a sharp clear image of lighted spots in the form of a circle when the drill is perpendicular to the surface being drilled is projected on the surface of the work being drilled.

5. An attachment for a hand held electric drill comprising a casing formed with a plurality of holes arranged in a circle concentric with the drill, a light source in said casing, a shield formed with a plurality of holes equal in number and concentric with the holes of said casing and in alignment therewith, interposed between said light source and said holes to screen all except rays of light substantially parallel to said drill, whereby a sharp clear image of lighted spots is projected on the surface of the work being drilled.

References Cited in the file of this patent UNITED STATES PATENTS 1,601,354 Elverson Sept. 28, 1926 1,826,004 Key Oct. 6, 1931 1,958,456 Warren May 15, 1934 2,072,286 Wellington Mar. 2, 1937 2,525,588 Cameron et al. Oct. 10, 1950 2,659,824 Burnham Nov. 17, 1953 2,670,427 Barlet et al. Feb. 23, 1954 FOREIGN PATENTS 842,835 Germany July 3, 1952 

